Records of medicinal plants and minerals date to ancient Chinese, Hindu, and Mediterranean civilizations. Ancient Greek physicians such as Galen used a variety of drugs in their profession. During the 16th century ad, after Western medicine began to recover from its long sleep during the Dark and Middle Ages, pharmaceutical practice began to develop rapidly. In 1546 the first pharmacopoeia (list of drugs and their preparation) appeared in Germany, and the profession of pharmacy is considered to have begun in 1617 with the founding of the Society of Apothecaries in London. Among the earliest modern pharmaceuticals were the anesthetics; morphine was first used in about 1804, ether in 1842, chloroform in 1847, and cocaine in 1860. Other substances isolated in the 19th century included strychnine (1817), quinine (1820), and nicotine (1828). Joseph Lister first used phenol (carbolic acid) to prevent infection in 1865.

Pharmaceuticals are generally classified by chemical group, by the way they work in the body (pharmacological effect), and by therapeutic use. Alkaloids were the first pure pharmaceuticals derived from natural substances (plants); they include quinine, nicotine, cocaine, atropine, and morphine. Drugs of animal origin include glandular extracts containing hormones, such as insulin for use in treating diabetes.

Antibiotics, vaccines, human blood-plasma fractions, and steroid hormones are other important pharmaceuticals manufactured from natural substances. Vitamins, which were formerly obtained from natural sources, are now often made in the laboratory.

In the preparation of dosages, many pharmaceuticals are ground to varying degrees of fineness. Many medicinal substances are added to water, alcohol, or another solvent so that they can be used in solution form. These may include spirits, elixirs, and tinctures. Ointments are one of many semisolid preparations, which also include creams, pastes, and jellies. Solid pharmaceuticals include pills, tablets, lozenges, and suppositories. In this form the compounds are more stable, with less risk of chemical reaction, and the dosage is easier to determine. Storage and packaging also is made simpler, and solid forms are more efficient to produce.